Concepts of ggplot2

Loading packages

package_check <- lapply(
  packages,
  function(x) {
    if (!require(x, character.only = TRUE)) {
      install.packages(x, dependencies = TRUE)
      library(x, character.only = TRUE)
    }
  }
)

Loading required package: tidyverse
Warning: package ‘ggplot2’ was built under R version 4.2.3Warning: package ‘tidyr’ was built under R version 4.2.3Warning: package ‘dplyr’ was built under R version 4.2.3Warning: package ‘stringr’ was built under R version 4.2.3── Attaching core tidyverse packages ──────────────────────────────────────────────────────────────────── tidyverse 2.0.0 ──
✔ dplyr     1.1.4     ✔ readr     2.1.4
✔ forcats   1.0.0     ✔ stringr   1.5.1
✔ ggplot2   3.5.0     ✔ tibble    3.2.1
✔ lubridate 1.9.2     ✔ tidyr     1.3.1
✔ purrr     1.0.2     ── Conflicts ────────────────────────────────────────────────────────────────────────────────────── tidyverse_conflicts() ──
✖ dplyr::filter() masks stats::filter()
✖ dplyr::lag()    masks stats::lag()
ℹ Use the ]8;;http://conflicted.r-lib.org/conflicted package]8;; to force all conflicts to become errors

The grammer of ggplot2

Load Data

bikes_df <- read_csv(file.path("data", "london-bikes-custom.csv"),
  col_types = "Dcfffilllddddc"
)

1- Data

initiate an empty canvas

2- Aesthetics

Maps data (variables) to the graph properties such as;

• positions(x,y)
• colours(colours, fill)
• shapes(shape, linetype)
• size(size)
• transparent(alpha)
• groupings(group)

3- Geometries

Interpret data (aesthetics) as graphs.

• points
• lines
• polygons
• text labels
• …

we may add visual properties to the graph

Mapping vs visual properties

Mapping

Visual properties

Mapping expresions

Global vs Local

DIV

1st column when browser is wide

ggplot(
    bikes_df,
    aes(x = temp_feel, y = count,
        color = season)
  ) +
  geom_point(
    alpha = .5
  )

… 2nd column when browser is wide

ggplot(
    bikes_df,
    aes(x = temp_feel, y = count)
  ) +
  geom_point(
    aes(color = temp_feel > 20),
    alpha = .5
  )

DIV format

1st column code

2st column code

1st column plot

2st column plot

END